The association between macroprolactin levels and vitamin D status in premenopausal women with macroprolactinemia: a pilot study

Abstract

Background: Macroprolactinemia is a frequent cause of misdiagnosis and mismanagement of patients with elevated prolactin levels. Its pathogenesis and clinical significance are still controversial.

Methods: The aim of this study was to investigate the relationship between elevated macroprolactin content and vitamin D status. The study population included 20 premenopausal women with isolated macroprolactinemia, 10 of whom were later treated with vitamin D (2 000 IU daily). Serum prolactin, macroprolactin, 25-hydroxyvitamin D and PTH levels were assessed at baseline and after 4 months of treatment.

Results: Compared with the control age- and weight-women with normal prolactin levels (n=11), patients with macroprolactinemia were characterized by lower levels of 25-hydroxyvitamin D and slightly higher levels of PTH. Vitamin D administered to patients with macroprolactinemia increased 25-hydroxyvitamin, reduced total prolactin and macroprolactin, as well tended to reduce PTH. The effect of vitamin D on total prolactin and macroprolactin correlated with their baseline values and baseline 25-hydroxyvitamin D levels.

Conclusions: The results of our study suggest the association between vitamin D status and elevated macroprolactin levels in premenopausal women.